Increasingly, vein by pass surgery is being used to circumvent the occluded or stenosed sites of coronary arteries and increase the blood flow to the myocardium. In the present study we plan to follow-up the patients with this type of surgery to find out whether a rigorous control of the risk factors, i.e., smoking, hyperlipemia, or hypertention, affects the post-surgery course of the disease. In addition, the possible effect of the surgery on quality of life is also investigated.